In recent years, with the start of terrestrial digital broadcasts and one-segment (one segment: one segment receiving services targeted for cell phones and mobile terminals) broadcasts (hereafter collectively referred to as “digital broadcasts”), terminal devices have been developing that can receive image streams such as digital broadcasts.
Examples of technology related to such terminal devices include content playback devices. The content playback devices play back a content distributed from a server storing pieces of contents via the Internet and an example thereof is described in Patent Document 1.
The content playback device described in Patent Document 1 is “a content playback device provided with a decoder and having functions of decoding content data received from a content-storing server via a network using the decoder and playing back content according to the content data and includes: determination means that determines whether content data received from the content-storing server conforms to a first format decodable by the decoder or a second format not decodable by the decoder; conversion means that converts content data according to the second format into content data according to the first format; and decoding target change means that, if the received content data conforms to the first format, considers the received content data as a decoding target of the decoder and if the received content data conforms to the second format, converts the received content data into the first format using the conversion means and then considers the converted content data as a decoding target of the decoder,” and operates as follows.
The content playback device includes, as firmware, a software encoder that can be updated as appropriate. If the content playback device transmits a request for transmission of music data, to the content-storing server and then receives music data transmitted by the content-storing server in response to the request and the received music data is a codec supported by the decoder, the content playback device sends the received music data to the decoder to play back the music. If the received music data is a codec not supported by the decoder, the content playback device encodes the received music data into music data conforming to a codec supported by the decoder using the software encoder and then sends the encoded data to the decoder to play back the music.
[Patent Document 1]
    Japanese Unexamined Patent Application Publication No. 2007-215099